import React, { Component } from 'react'

export default class Count extends Component {

  increment=()=>{
    const {value} = this.selectNumber
    this.props.jia(value*1)
  }
  decrement=()=>{
    const {value} = this.selectNumber
    this.props.jian(value*1)
  }
  incrementIfOdd=()=>{
    const {value} = this.selectNumber
    if(this.props.count % 2 !== 0 ){
      this.props.jia(value*1)
    }
  }
  incrementAsync=()=>{
    const {value} = this.selectNumber
    this.props.jia(value*1)
  }
  render() {
    console.log(this.props);
    return (
      <div>
        <h1>当前求和为：{this.props.count}</h1>
        <select ref={c=> this.selectNumber = c }>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>&nbsp;
        <button onClick={this.increment} >+</button>&nbsp;
        <button onClick={this.decrement} >-</button>&nbsp;
        <button onClick={this.incrementIfOdd} >当前求和为奇数再加</button>&nbsp;
        <button onClick={this.incrementAsync} >异步加</button>
      </div>
    )
  }
}
